The use of piezoelectric transducers to measure, monitor and track various events is not new in the art. Currently, manufacturers are using magnetic Hall effect transducers, photo optic transducers, Light Emitting Diode transducers and the like to monitor gas pumps, automotive engines, or measure events taking place in manufacturing processes, and the like, where gas pumps are utilized, wherein most pumps in use today are air driven pumps.
Some pressure sensing applications in which piezoelectric transducers have been used are: the actual measurement of pressure; measuring impact forces through the use of accelerometers; use of microphones for recording or detection of sound; the generation of sounds and/or ultrasonic waves; and, the detection of passing automobiles or trains over strings of transducers.
The industry has used electronic feedback from operating pumps in some critical applications for a number of years. The feedback has been carried out in a number of ways. Traditionally, in gas operated pumps, at least one part typically reciprocates. Some pump manufacturers use electronically shifting shuttle valves within or attached to these pumps. Such shifting has been accomplished by a reciprocating portion of the pump being detected with a proximity transducer, or by a color-contrasting portion of a reciprocating part in the pump passing an electronic eye, which in turn sends an electronic signal to a shuttle valve. This movement in turn shifts the shuttle valve.
Other pump manufacturers have used both mechanical and solid-state pressure switches, which receive a blast of gas from valves inside the pump at the desired time of shuttle valve switching. The mechanical or solid-state pressure switch then translates the blast of gas into an electronic signal that is then sent on to the shuttle valve for operation of the shuttle valve. In addition, the electronic signals that are sent to the shuttle valve can and have been tapped by manufacturers to provide electronic signals to other apparati that monitor the pumps. These apparati include but are not limited to: cycle counting transducers, tachometers, overrun monitors, underrun monitors and personal computer systems which are embedded in tools which monitor pumps, among other things.
In every case, the use of such current equipment requires invasive transducer placement in the pump itself. This creates a situation where the parts placed in the interior of the pump cause contamination, or the parts are affected by the caustic, acid, or other destructive chemicals being handled by the pump. Such parts include, fox example, flow meters, mass transducers, and paddle wheel transducers, all of which are placed directly in the flow of the materials being handled by the pump. In the case of foods, such parts create situations wherein the food is contaminated by trace metals and other materials. Also, the placement of these parts in the interior of the pump creates a situation wherein the parts act as plugs or create plugs, or partial plugs, in the flow of the material being handled by the pump, and in addition, these parts are difficult to replace or repair.
In other situations, owing to the above stated problems, pump systems are not monitored at all and this leads to malfunctions in component parts of the manufacturing process and thus also leads to expensive downtime, cleanup and myriad other problems. In these situations, the only time that the pump is monitored is when there is a major malfunction that happens to be noticed by those monitoring the manufacturing process. The ultimate is when these problems cause the pump to stop completely, which often leads to human injury and equipment destruction.
Thus, it would be valuable to have a means of monitoring and/or controlling pumps and investigating automotive engine problems by a non-invasive transducer that would essentially eliminate all of the above-mentioned problems.
Transducers that are capable of monitoring and/or controlling by a non-invasive transducer can be found in U.S. Pat. No. 6,484,589, issued on Nov. 26, 2002; U.S. Pat. No. 6,609,416, issued on Aug. 26, 2003; U.S. Pat. No. 6,823,742 issued on Nov. 30, 2004; U.S. Pat. No. 7,040,149 issued on May 9, 2006, and U.S. Pat. No. 7,096,726 issued on Aug. 29, 2006. All of these deal with transducers that are hard wired and are susceptible to damage. These transducers do not provide the quality or the protection that the transducers of the instant invention do.